This project incorporates a large number of diverse conditions, ranging from inborn errors of metabolism, to cerebral degenerations, to the brain dysfunction of diverse etiology. The unifying factors are cerebral involvement, determination of pathogenesis and therapeutic trials. The methodological approach includes clinical, and genetical apprasial, brain pathology through cerebral biopsies when indicated, post mortem obtained material, tissue culture as well as biochemical determination of content and composition of basic compounds and estimation of respective enzyme activities.